U.S. patent application number 16/641766 was filed with the patent office on 2020-07-09 for inflator, method of manufacturing the same and module including said inflator.
The applicant listed for this patent is TRW AUTOMOTIVE GMBH. Invention is credited to Stefan Bachmann.
Application Number | 20200216007 16/641766 |
Document ID | / |
Family ID | 63557391 |
Filed Date | 2020-07-09 |
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United States Patent
Application |
20200216007 |
Kind Code |
A1 |
Bachmann; Stefan |
July 9, 2020 |
INFLATOR, METHOD OF MANUFACTURING THE SAME AND MODULE INCLUDING
SAID INFLATOR
Abstract
The invention describes an airbag (10) for a vehicle occupant
restraint system, wherein the airbag (10) in the inflated state
includes a front side (24) forming an occupant impact surface and
an opposite rear side (22). The front side (24) and the rear side
(22) are formed by shell portions (14, 16) of the airbag (10) being
connected to each other at their outer edges (34, 36). The front
side (24) is longer along a centerline (M) extending in the
longitudinal direction of the airbag (10) than the rear side (22)
so that, in the inflated state, the airbag (10) takes a curved
shape. The front side (24) has at least one shaping line (42)
extending substantially curved and transversely to the centerline
(M) at which shaping line two shell portions (34, 36) are connected
to each other. The respective outer edges (34, 36) of the front
side (24) and the respective outer edges (34, 36) of the rear side
(22) are of the same overall length.
Inventors: |
Bachmann; Stefan;
(Heimbuchenthal, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TRW AUTOMOTIVE GMBH |
Alfdorf |
|
DE |
|
|
Family ID: |
63557391 |
Appl. No.: |
16/641766 |
Filed: |
August 7, 2018 |
PCT Filed: |
August 7, 2018 |
PCT NO: |
PCT/EP2018/071403 |
371 Date: |
February 25, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60R 21/2035 20130101;
B60R 21/231 20130101; B60R 2021/23169 20130101; B60R 2021/23533
20130101 |
International
Class: |
B60R 21/203 20060101
B60R021/203 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 4, 2017 |
DE |
10 2017 120 238.2 |
Claims
1-11. (canceled)
12. An airbag (10) for a vehicle occupant restraint system, wherein
the airbag impact surface and an opposite rear side (22), the front
side (24) and the rear side (22) being formed by shell portions
(14, 16) of the airbag (10) which are connected to each other at
their outer edges (34, 36), wherein the front side (24) along a
centerline (M) extending in the longitudinal direction of the
airbag (10) is longer than the rear side (22) so that in the
inflated state the airbag (10) takes a curved shape, wherein the
front side (24) includes at least one shaping line (42) extending
substantially curved and transversely to the centerline (M) at
which shaping line two shell portions (14, 16) are connected to
each other, wherein the respective outer edges (34, 36) of the
front side (24) and the respective outer edges (34, 36) of the rear
side (22) are of the same overall length.
13. The airbag (10) according to claim 1, wherein the airbag (10)
is configured free from gathering.
14. The airbag (10) according to claim 1, wherein the shell
portions (14, 16) are formed by separately configured shell parts
(18, 20).
15. The airbag (10) according to claim 1, wherein the two shell
portions (14, 16) include an edge contour (38, 40) which safeguards
the respective outer edges (36) of the front side (24) and the
respective outer edges (34) of the rear side (22) to have the same
overall length.
16. The airbag (10) according to claim 1, wherein at least one of
the shell portions (14, 16) in the cut (12) includes an edge
contour (38, 40) extending substantially convexly and transversely
to the centerline.
17. The airbag (10) according to claim 5, wherein the edge contour
(38, 40) extending substantially transversely to the centerline (M)
includes plural subareas (46-56) which are different in shape.
18. The airbag (10) according to claim 6, wherein the subareas
(46-56) are formed to be straight, substantially convex and/or
substantially concave.
19. The airbag (10) according to claim 5, wherein the edge contour
(38, 40) extending substantially transversely to the centerline (M)
exhibits a continuous geometry and is especially arc-shaped.
20. The airbag (10) according to claim 1, wherein the at least one
shaping line (42) which extends substantially curved and
transversely to the centerline (M) is formed at least partially by
a seam (44).
21. The airbag (10) according to claim 1, wherein the two shell
portions (14, 16) are joined by stitching in the area of the edge
contour (38, 40) extending substantially transversely to the
centerline (M), especially wherein the seam (44) at least partially
constitutes the shaping line (42).
22. The airbag (10) according to claim 20, wherein the seam (44)
includes plural partial seam portions (58-62) being different in
shape.
Description
[0001] The invention relates to an airbag for a vehicle occupant
restraint system, especially a so-called knee airbag.
[0002] From prior art, airbags are known for use in an automotive
vehicle to protect a vehicle occupant in the area of his/her knee,
for example. Airbags of this type are also referred to as knee
airbags. Usually two different types of configuration of knee
airbags are differentiated in which the airbags are arranged in the
visible area and, resp., in the hidden area inside the automotive
vehicle. In the knee airbags arranged in the visible area a visual
cover is provided, for example, which, as a rule, is disposed
beneath the steering wheel lining on the driver side and, resp.,
beneath the glove box on the passenger side. The knee airbags
arranged in the hidden area are arranged, for example, beneath or
behind an instrument panel.
[0003] In knee airbags arranged in the hidden area and, resp., in
the corresponding airbag modules, the airbag must deploy upwards
about the lower edge of the instrument panel to efficiently protect
the vehicle occupant, especially in the area of his/her knee.
Accordingly, in the inflated state the airbag takes a curved shape
which extends starting from the hidden area beneath or behind the
instrument panel around the instrument panel. In order to influence
the inflation behavior of the airbag in a desired manner, the
airbag requires specific control mechanisms.
[0004] In prior art, this is usually achieved by designing the rear
side of the airbag in the inflated state to be shorter than the
front side, with the length of the rear side being shortened by
providing a fabric gathering on the rear side causing the at least
one shell portion of the airbag forming the rear side to be partly
gathered.
[0005] It has turned out to be a drawback that manufacture is
complicated as a separate manufacturing step is required to produce
the fabric gathering. In addition, higher manufacturing costs are
incurred due to the additional manufacturing step and the
additionally used material. Furthermore, a higher limit of accuracy
must be observed during manufacture to ensure the airbag to deploy
in a desired manner. Moreover, the folded airbag requires a larger
construction space due to the fabric gathering, as fabric
accumulates in the area of the fabric gathering.
[0006] It is the object of the invention to provide an airbag for a
vehicle occupant restraint system which can be used especially as a
knee airbag, wherein the latter requires little space and can be
manufactured at low cost.
[0007] According to the invention, the object is achieved by an
airbag for a vehicle occupant restraint system, wherein, in the
inflated state, the airbag has a front side forming an occupant
impact surface and an opposite rear side, the front side and the
rear side being formed by shell portions of the airbag which are
connected to each other at their outer edges, with the front side
along a centerline extending in the longitudinal direction of the
airbag being longer than the rear side so that in the inflated
state the airbag takes a curved shape, the front side exhibiting at
least one shaping line extending substantially curved and
transversely to the centerline at which shaping line two shell
portions are connected to each other, wherein the respective outer
edges of the front side and the respective outer edges of the rear
side exhibit the same overall length.
[0008] It is the basic idea of the invention to manufacture the
airbag in a more space-saving and thus simpler manner by dispensing
with the rear fabric gathering. Accordingly, the required
construction space of the folded airbag can be reduced. In
addition, the material required for the additional fabric gathering
as well as the additional mounting and, resp., manufacturing step
can be saved. Since the respective outer edges, i.e. the outer
contour, of the front side and the rear side are equal, it is
ensured that the respective outer edges can be stitched to each
other free from creases.
[0009] The substantially curved shaping line extends on the front
side facing the vehicle occupant, wherein the shaping line extends
transversely, when viewed in the vehicle direction. The shaping
line separates or, resp., defines different chambers within the
three-dimensionally designed airbag, especially as regards the size
and/or shape. The substantially curved extension of the shaping
line on the front side is defined already by three points, for
example two points in the area of the outer edges and one point in
the area of the centerline. If a shaping line shows a curvature
across said three points, a substantially curved extension of the
shaping line is given.
[0010] One aspect provides that the airbag is designed free from
gathering. Accordingly, it is ensured for a knee airbag that it
inflates in a desired manner and thus takes a curved shape in the
inflated state. Accordingly, a fabric gathering for controlling the
inflation behavior, especially a fabric gathering on the rear side,
can be dispensed with.
[0011] According to another aspect, the shell portions are formed
by separately designed shell parts. The airbag, especially the cut
thereof, is thus formed in several parts. The individual shell
parts are stitched to each other to design the shape of the airbag.
Accordingly, the shaping line extending substantially curved and
transversely to the centerline can be produced.
[0012] As an alternative, the airbag is made from one single shell
part. The shell part may comprise several shell portions which are
formed, for example, by seams and/or folding. The one shell part
thus can be folded so that appropriate shell portions which are
fixed by seams will be formed. The shaping line extending
substantially curved and transversely to the centerline can be
formed at least in portions by a seam. For example, the shaping
line extends along a folding and at least one seam.
[0013] Another aspect provides that the two shell portions have an
edge contour that safeguards the respective outer edges of the
front side and the respective outer edges of the rear side to be of
the same overall length. If the shell portions are formed by
separate shell parts, each of the latter exhibits an edge contour
which is recessed toward the outer edges to ensure that the
respective outer edges of the front and rear sides are in
concurrent as to length.
[0014] The edge contour recessed toward the outer edges can be
realized by removing fabric material, with the removed fabric
material corresponding to the otherwise provided fabric
gathering.
[0015] If one single shell part is present, the respective shaping
line extends in such curved manner that the respective outer edges
of the front side and the respective outer edges of the rear side
are of the same overall length. Accordingly, the seam extends in a
recessed manner relative to the outer edges. The seam being
recessed at the outer edges defines excessive fabric material, i.e.
the fabric material from the seam to the edge, with the excessive
fabric material corresponding to the fabric material otherwise
provided for fabric gathering.
[0016] In general, the respective front-side shell portions which
are interconnected via the shaping line thus are designed so that
the outer edges of the front side and those of the rear side are
equal in the overall length.
[0017] According to one embodiment, at least one of the shell
portions in the cut has an edge contour extending substantially
convexly and transversely to the centerline. This ensures the
respective shell portion to be formed recessed vis-a-vis its
central area in the area of its outer edges.
[0018] In particular, the edge contour extending substantially
transversely to the centerline has plural subareas taking different
shapes. Accordingly, the edge contour may exhibit a particular
geometry ensuring that, on the one hand, the front side along a
centerline extending in the longitudinal direction of the airbag is
longer than the rear side and, on the other hand, the respective
outer edges of the front and rear sides are equal in the overall
length.
[0019] Especially, the subareas have a straight, substantially
convex and/or substantially concave design. Accordingly, the
subareas may be formed differently, for example opposed, to ensure
that the edge contour of the respective shell portions extending
transversely to the centerline which are interconnected via the
shaping line takes the desired shape. In this way, it is ensured
that the outer edges of the airbag can be stitched to each other
free from creases, as the outer edges are equal in length.
[0020] According to another embodiment, the edge contour extending
substantially transversely to the centerline has a continuous
geometry. The continuous geometry is defined by the fact that it
can be described by a steady function which can especially be
differentiated. For example, especially such edge contour has no
plural subareas of different shape. The continuous geometry of the
edge contour can be subdivided into different subareas,
however.
[0021] Especially, the edge contour extending transversely to the
centerline is arc-shaped. This ensures the respective shell portion
to take a shape that is recessed vis-a-vis its central area in its
outer edge zones.
[0022] Another aspect provides that the at least one shaping line
extending substantially curved and transversely to the centerline
is formed at least partially by a seam. The seam may be provided at
the single shell part to configure the different shell portions.
The seam also may be provided in part only, if the fabric material
of the corresponding shell part is folded, for example.
Furthermore, shell parts designed separately from each other can be
connected to each other via the seam.
[0023] According to another aspect, the two shell portions are
stitched to each other in the area of the edge contour extending
substantially transversely to the centerline, especially wherein
the seam at least partially forms the shaping line. Thus, the
respective shell portions are designed via a seam. If the airbag is
made from plural shell parts, the shaping line, viz. the seam
forming the shaping line, extends in the area of the corresponding
edge contours of the shell parts.
[0024] If the airbag is made from one single shell part, the seam
extends in a defined area to configure the shell portions in a
desired way. The shaping line may be produced by the seam and a
folding.
[0025] According to one embodiment, the seam extends substantially
in parallel to the edge contour. As a consequence, the spaces of
the seam are substantially equal to the corresponding edge
contour.
[0026] Another embodiment provides the seam to extend independently
of the edge contour. Consequently, the seam may take a shape
extending substantially convexly and transversely to the centerline
with respect to the edge contour.
[0027] The seam may include several partial seam portions which
take different shapes. For example, the partial seam portions are
straight, substantially convex and/or substantially concave.
[0028] Further advantages and characteristics of the invention will
be evident from the following description and the drawings which
will be referred to and wherein:
[0029] FIG. 1 shows a schematic view of a cut of an airbag
according to the invention as set forth in a first embodiment,
[0030] FIG. 2 shows a partial view of a cut of an airbag according
to the invention as set forth in a second embodiment,
[0031] FIG. 3 shows a partial view of a cut of an airbag according
to the invention as set forth in a third embodiment,
[0032] FIG. 4 shows a partial view of a cut of an airbag according
to the invention as set forth in a fourth embodiment,
[0033] FIG. 5 shows a partial view of a cut of an airbag according
to the invention as set forth in a fifth embodiment,
[0034] FIG. 6 shows a partial view of a cut of an airbag according
to the invention as set forth in a sixth embodiment,
[0035] FIG. 7 shows a partial view of a cut of an airbag according
to the invention as set forth in a seventh embodiment, and
[0036] FIG. 8 shows a partial view of a cut of an airbag according
to the invention as set forth in an eighth embodiment.
[0037] FIG. 1 illustrates an airbag 10 in the non-stitched state
which can be used as a knee airbag. The airbag 10 is part of a
vehicle occupant restraint system in an automotive vehicle for the
protection of a vehicle occupant. Usually, the airbag 10 together
with an inflator not shown here constitutes an airbag module.
[0038] Since the airbag 10 is illustrated in the non-stitched
state, a corresponding cut 12 of the airbag 10 is shown which, in
the illustrated embodiment, consists of two shell portions 14, 16
formed by separately configured shell parts 18, 20.
[0039] The first shell portion 14 in the illustrated embodiment
forms a rear side 22 of the airbag 10 in the inflated state. In
addition, the first shell portion 14 partly forms a front side 24
of the airbag 10 in the inflated state. Accordingly, the first
shell portion 14 includes a rear side face 26 forming a first area
28 of the cut 12 and a partial front side face 30 which, together
with the second shell portion 16, forms the front side 24 of the
airbag 10 in the inflated state. The partial front side face 30 and
the second shell portion 16 together constitute a second area 32
which is formed by the two shell parts 18, 20 in the shown
embodiment.
[0040] As a consequence, the first area 28 corresponds to the rear
side 22 of the airbag 10, whereas the second area 32 corresponds to
the front side 24 of the airbag 10.
[0041] In general, the front side 24 of the airbag 10 provides, in
the inflated state thereof, an occupant impact surface via which
especially at least one knee of the vehicle occupant is
protected.
[0042] In FIG. 1, a folding line F is shown in a broken line
located between the two areas 28, 32. Along the folding line F the
first shell portion 14 is folded to design the cut 12 such that it
can be stitched so as to form the (three-dimensional) airbag 10. A
centerline M defining the longitudinal direction of the first shell
portion 14 and the second shell portion 16 is perpendicular to said
folding line F.
[0043] The two shell portions 14, 16 are configured such that the
rear side 22 of the airbag 10 in the joined state has a smaller
length than the front side 24 in the area of the centerline M, thus
ensuring that the airbag 10 in the inflated state inflates around
an instrument panel. Therefore, the airbag 10 in the inflated state
takes a curved shape, viz. in the z direction.
[0044] Further, it can be seen from FIG. 1 that the cut 12 is
configured so that outer edges 34 of the rear side 22 as well as
outer edges 36 of the front side 24 formed by the partial front
side face 30 and the second shell portion 16 are of the same
overall length.
[0045] This means that, when folding the partial front side face 30
and, resp., when folding the first shell portion 14 about the
folding line F, it is ensured that the corresponding outer edges
34, 36 are superimposed free from creases so that they can be
easily joined by stitching.
[0046] Each of the two shell portions 14, 16 formed by separately
formed shell parts 18, 20 moreover includes an edge contour 38, 40
via which the two shell portions 14, 16 are connected to each
other.
[0047] The two shell portions 14, 16 are joined by stitching along
a shaping line 42 so that a corresponding seam 44 is formed, when
the two shell portions 14, 16 are connected to each other. The
shaping line 42 defines chambers within the three-dimensional
airbag 42.
[0048] The thus formed shaping line 42 is therefore located on the
front side 24 of the airbag 10, with the shaping line 42 extending
substantially transversely to the centerline M, as is evident from
FIG. 1. Further, the shaping line 42 does not extend in a straight
way, but in a substantially curved way and thus in the y
direction.
[0049] In general, the shaping line 42 as well as the edge contours
38, 40 extend substantially in parallel to the folding line F, viz.
substantially transversely to the centerline M.
[0050] In the shown embodiment, both the shaping line 42 and,
resp., the seam 44 and the edge contours 38, 40 are designed so
that they are recessed in the outer edge zones, the areas close to
the outer edges 36, vis-a-vis the central area, viz. vis-a-vis the
area along the centerline M.
[0051] This guarantees that the respective outer edges 34, 36 of
the rear and front sides 22, 24 coincide so that the cut 12 can be
stitched free from creases at the outer edges 34, 36 in the folded
state to design the airbag 10. At the same time, the front side 24
is longer than the rear side 22 in the area of the centerline M so
that the desired inflation behavior is resulting.
[0052] Each of the respective edge contours 38, 40 of the two shell
portions 14, 16 has several subareas 46 to 56. The first edge
contour 38 of the first shell portion 14 correspondingly has three
subareas 46 to 50, whereas the second edge contour 40 of the second
shell portion 16 equally comprises three subareas 52 to 56. The
respective subareas 46 to 56 are formed in pairs corresponding to
each other.
[0053] In total, the two edge contours 38, 40 have a substantially
convex shape. The respective subareas 46 to 56 are differently
designed, however, so that they take different shapes. For example,
the subareas 46, 50, 52, 56 located toward the respective outer
edges 36 take a shape that ensures the fabric material to be
recessed in these areas vis-a-vis the central areas of the first
shell portion 14 and the second shell portion 16. The fact that the
fabric material is recessed in the subareas 46, 50, 52, 56 is
resulting from the surfaces formed between the edge in the subareas
46, 50, 52, 56 and the broken lines which constitute steady
extensions of the subareas 48, 54.
[0054] This ensures that the outer edges 34, 36 of the two shell
portions 14, 16 coincide, viz. have the same overall length.
Moreover, it is ensured that the rear side 22 is shorter than the
front side 24 as far as the length along the centerline M is
concerned, which safeguards the desired inflation behavior.
[0055] Concretely speaking, the subareas 46, 50, 52, 56 located in
the area of the respective outer edges 36 take a concave shape,
whereas the other subareas 48, 54 take a convex shape. Since,
however, the subareas 48, 54 are predominant, the two edge contours
38, 40 substantially take a convex shape.
[0056] The shaping line 42 and, resp., the seam 44 in the
illustrated embodiment extends in parallel to the edge contours 38,
40 so that also the shaping line 42 and, resp., the seam 44 has
plural partial seam portions 58 to 62. The first partial seam
portion 58 is assigned to the subareas 46, 52, the second partial
seam portion 60 is assigned to the subareas 48, 54 and the third
partial seam portion 62 is assigned to the subareas 50, 65, as is
illustrated in FIG. 1.
[0057] In this respect, each of the first and third partial seam
portions 58, 62 takes a concave shape, whereas the second partial
seam portion 60 takes a convex shape. In total, the seam 44 and,
resp., the shaping line 42 takes a substantially convex shape.
[0058] In FIGS. 2 to 8, further embodiments are shown in which
merely the second area 32 and thus the one defining the front side
24 is illustrated.
[0059] The edge contours 38, 40 and/or the shaping line 42 and,
resp., the seam 44 in these embodiments, especially the subareas 46
to 56 and, resp., the partial seam portions 58 to 62, exhibit
different shapes.
[0060] FIG. 2 illustrates, for example, that the edge contours 38,
40 have a continuous geometry. Consequently, the subareas 46 to 56
are configured so that the corresponding edge contours 38, 40 can
be described by a steady, especially differentiable, function. This
is equally applicable to the shaping line 42 and, resp., the seam
44 and the corresponding partial seam portions 58 to 62, as the
shaping line 42 and, resp., the seam 44 extends in parallel to the
edge contours 38, 40.
[0061] FIG. 3 illustrates an embodiment in which merely the shaping
line 42 and, resp., the seam 44 shows a continuous geometry so that
the partial seam portions 58 to 62 can be described by a steady,
especially differentiable, function. The edge contours 38, 40, on
the other hand, are straight so that fabric material projects from
the corresponding edge zones. Said projecting fabric material may
also be referred to as excessive fabric material which, in terms of
quantity, corresponds to the fabric material which otherwise would
have been used for the fabric gathering on the rear side 22.
[0062] In the embodiments according to FIGS. 2 and 3, the shaping
line 42 and, resp., the seam 44 are designed to be substantially
curved on the front side 24 of the airbag 10.
[0063] The embodiment according to FIG. 4 differs from the one from
FIG. 3 to the effect that the shaping line 42 and, resp., the seam
44 is formed by straight partial seam portions 58 to 62. The
respective partial seam portions 58 to 62 are arranged at an angle
with each other, especially in mirror-symmetry to the centerline M.
Therefore, a substantially curved shaping line 42 and, resp., seam
44 is resulting, as the two partial seam portions 58, 62 facing the
edge zones extend to be recessed vis-a-vis the central partial seam
portion 60.
[0064] In general, thus the fabric material of a respective shell
portion 14, 16 extending to the shaping line 42 and, resp., seam 44
is decisive. In the area of the centerline M, the fabric material
has a larger length up to the shaping line 42 and, resp., seam 44
than in the edge zones provided in the area of the corresponding
outer edges 36.
[0065] FIGS. 5 to 7 illustrate further embodiments which are
different from those of the FIGS. 1 to 4 in that the two shell
portions 14, 16 are formed by one single shell part 64 which is
folded along a folding line U to form the two shell portions 14,
16. The single shell part 64 is thus folded along the folding line
U so that a folding 66 is formed. The folding at least partially
constitutes the shaping line 42.
[0066] Accordingly, the folding 66 substantially corresponds to the
first edge contour 38 of the first shell portion 14 as set forth in
the embodiment shown in FIG. 4, with the airbag 10 being already
gastight in the area of the folding 66.
[0067] In the embodiment according to FIG. 5, the seam 44 extends
analogously to that of FIG. 4.
[0068] The embodiments according to FIGS. 6 and 7 substantially
correspond to those of the FIGS. 5 and 1, with the seam 44 being
provided only partially, as it runs into the folding 66 and thus
directly into the folded edge. In these embodiments, the shaping
line 42 is thus formed by the seam 44 and the folding 66.
[0069] In the embodiment shown in FIG. 6, merely the partial seam
portions 58, 62 are shown as compared to the embodiment according
to FIG. 5, as the central partial seam portion 60 would coincide
with the folding 66.
[0070] In the embodiment shown in FIG. 7, the central partial seam
portion 60 is configured merely partially in the transition area to
the partial seam portions 58, 62, until the central partial seam
portion 60 runs into the folding 66.
[0071] As is evident from FIGS. 1 to 7, the shaping line 42 is
always configured substantially transversely to the centerline M as
well as in curved shape, as the shaping line 42 is recessed in the
edge zones, viz. at the outer edges 36, vis-a-vis the central area
at the centerline M.
[0072] The shaping line 42 can be formed completely by the seam 44,
as illustrated in the embodiments according to FIGS. 1 to 5, or
partially by the seam 44 and the folding 66.
[0073] In general, the shaping line 42 thus comprises a contour
through which the outer edges 34, 36 of the rear and front sides
22, 24 are ensured to be equal in length and the front side 24
nevertheless is ensured to be longer than the rear side 22 in the
area of the centerline M, which results in the desired inflation
behavior of the airbag 10.
[0074] Especially, this is achieved by at least the partial seam
portions 58, 62 which run into the outer edges 36 of the front side
24, wherein the partial seam portions 58, 62 ensure the shaping
line 42 in the area of the outer edges 36 to run back vis-a-vis the
central area at the centerline M. Hence, the partial seam portions
58, 62 run away from the folding 66 and, resp., from the
corresponding edge contour 38, 40 in the area of the outer edges
36. This results in the substantially curved shape of the shaping
line 42 on the front side 24.
[0075] In FIG. 8, another embodiment is illustrated which differs
from the other embodiments by the fact that the airbag 10 and,
resp., the cut 12 has a third shell part 68 in the form of an
insert which is interposed between the two shell parts 18, 20.
[0076] In the shown embodiment, the edge contours 38, 40 as well as
the seam runs of the two shell parts 18, 20 are formed analogously
to those of the shell parts 18, 20 according to FIG. 4. The third
shell part 68 serving as an insert is configured to be
appropriately corresponding.
[0077] Also, further inserts may be provided so that the airbag 10
can be formed of more than three shell parts. The individual shell
parts are connected to each other via corresponding shaping lines
42 which therefore are connecting lines.
[0078] In general, the shapes of the seams 44 may be provided to be
interchangeable, in particular the shapes of the seams 44 of the
embodiments according to FIGS. 1 to 4 can be applied to the other
embodiments.
[0079] Generally, an airbag 10 is provided which can be used as a
knee airbag and requires little construction space, wherein the
airbag 10 moreover can be manufactured at low cost. Since the
airbag 10 can be used as knee airbag, the inflation behavior
thereof can thus be controlled in a desired manner.
* * * * *